I too would very much like a way to exclude certain slaves but have not had time to look at the code. For many of my applications I have masters of rather marginal power and dozens of slaves around the world. I quite frequently want to check certain slaves during their regional off hours - not all slaved at once.

I have installed Percona Toolkit for using pt-table-checksum utility. We have a master and 4 slaves. 'pt-table-checksum' utility when executed on master checks on all slaves for discrepancies.
My requirement is to checksum selective slave (as and when free) and not all slaves at a time.

After going through the documentation, I found that this can be achieved using --recursion-method=dsn option. Hence, I created a table 'dsns' in 'some_database' as per the documentation.
I entered the host name that I wanted to check in 'dsns' table like 'h=10.10.12.21' (i.e., Slave).
Then I tried the following command: shell]# pt-table-checksum --lock-wait-time=50 --nocheck-replication-filters --replicate-check --recursion-method=dsn=D=some_database,t=dsns --user=username --password=password --databases=some_database --tables=some_table
But the above command executes check on all 4 slaves.

If I execute command with h=10.10.12.21 on command line, it executes considering given server as Master server which is not the case.

Please suggest the correct method for checksuming selective slaves out of four.